Andrew Bayley Posted June 1, 2001 Share Posted June 1, 2001 I am going I-N-S-A-N-E-!-!-! I spent the past 48 hours trying to figure out why my P.O.S. wont run right. Let's recap, shall we: Pulled the motor over the winter to redo the trans. Put the motor back in and started up fine with open headers this Spring. I would fire it up ever now and then to "impress" guest's with the loudness of open headers, but I would never really run it for more than about 30 seconds. Finally, I get something that resembles and exhaust on it and I go to crank it over. Rrrr...rrrr...rrr...rrr...rrr... ... ...rrr...rrr...rrr... ... ... ...rrr...rrr...rrr... nothing nadda zero zilch Darn thing wont even kick. I quickly suspect the very old magnetic pickup in my HEI distributor is bad. I replaced the old distributor with a "shiny" new MSD unit (with all new wires to boot!) I get the motor to fire, but it starts running like schit. In my denial of a bigger problem, I take the car around the block for a quick test drive. Wow, she is running R-E-A-L-L-Y bad... were talking Chrysler 3.0L V6 bad! My next guess was that the cam timing skipped a beat. Pulled off a valve cover and checked number one cylinder valves in relation to TDC. Yup, exhaust was still open way past TDC (OK, I know it's not the "real" TDC, but it's when the pointer is falsely point to TDC). Ripped off the timing cover and sure enough, cam gear skipped a tooth. Chain had a good deal of slop, but it was only about 5 years old and didn't really have that many miles on it. Replaced it anyway, better safe than sorry. Get everything back together, say a few Hail Mary's, and take another turn. The cam timing feels correct, but there is still a miss somewhere. Very inconsistant. Runs great when I'm costing with my foot off the gas, but once I get into it, things get ugly. All sorts of popping and farting from unburned gas. First thing, I pull the coil and have that checked at the local speed shop (Hey, those "sparking" MSD display's are good for something after all!!!) Next, I check the power leads going to the MSD 6AL box. Perfect. Next, I check to make sure the engine has a good ground. Yup, everything fine there. Finally, I pull the plugs to inspect their condition. Hmmm... Very blackened. How bad do plugs have to be before they cause an engine to run this rough? I'm starting to wonder if the all the carbon in addition to the larger 0.040" gap I use is causing such a problem. I though MSD was supposed to cut through these types of conditions. Speaking of which, what gap size do other people use with their MSD boxes? Please, this is really starting to frusturate me. Life has no meaning with the Z8... Well OK, so maybe it does, it's just not a fast Any suggestions welcome. Free rides in the drivers seat for anyone who actually comes over and fixes the thing for me! I'm not one to easily announce defeat, but this has been a very long, painful battle. Thanks -Andy Quote Link to comment Share on other sites More sharing options...
jeromio Posted June 1, 2001 Share Posted June 1, 2001 I have <b>alot</b> of experience with fouled plugs. For whatever reason, my L28 has a plug fouling poltergeist in it. It leaves for long periods of time, only to re-appear. To answer at least one of your questions, it doesn't take much of a fouling to cause an engine to run like crap. And it only takes one plug to ruin the party. More than one plug (on the 6 cyl) and the thing will not want to run at all. I had a problem with my wife's truck - some schmuts got in between the points and caused some ignition problems. This in turn lead to 2 fouled plugs. SO, if your distro went spazmo, it could very likely have caused some plugs to foul (weak spark can do that). Change out all the plugs. If you've already done that and the new ones got fouled too, then I'm all outta answers. Quote Link to comment Share on other sites More sharing options...
TimZ Posted June 1, 2001 Share Posted June 1, 2001 Jeromio is right - if your plug has become carbon fouled, it can definitely wreak havok. What actually happens is that the carbon bonds to the insulator, and creates a short circuit from the center electrode to ground. This makes it pretty much impossible for the plug to generate a spark, since all the energy gets dissipated through the carbon. You do have an option, before ditching the plugs, though. It is possible to clean the plugs once they are fouled. The only effective way to do this that I have found is to use a propane torch (Bernz-o-matic, etc) to burn the carbon off the plug. You have to get the plug tip red hot, until the ceramic insulator starts looking white again, all around the tip. AFAIK, this is the only thing that will remove the carbon deposits - no amount of carb cleaner or solvents will budge it. If you want, bring them by this weekend and I'll clean them for you... Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted June 1, 2001 Share Posted June 1, 2001 Heh, I hav one of those little sandblaster things hooked to my air compressor made just for plugs. I've not yet used it but I'm confident it'll work Cheap too! The Mustang's tune is off due to a missing O2 sensor so it fouls plugs in minutes. Yes, it doesn't take much to ruin the plug! Getting the carbon off will likely fix you right up... Quote Link to comment Share on other sites More sharing options...
Drax240z Posted June 1, 2001 Share Posted June 1, 2001 Don't ever rule out plugs as a problem!!!!!! I've been there, and learned from experience. A buddy of mine had a 78 chev truck, with a rebuilt 350. Good rebuildt, no problems except an off-idle stumble. Finally we tried to track it down because it was annoying him. First thought was cap, rotor, wires, coil. All good. Carb... we swapped on a spare, same problem. Fuel pump? Well for $17 lets replace it anyway. Vacuum leaks? Nope. PCV? Fine. Well maybe its those cheap wires, nope. You get the idea. We checked the plug gap, and colouration, all was good. Turns out the plugs were slightly shorter than they needed to be for these heads though, new plugs and all was good! Its usually those little details that cause all the problems. Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted June 2, 2001 Author Share Posted June 2, 2001 Thanks for the advice guys. I think I'm gonna just ditch the plugs I've got and start off with a new set. Besides, I was never really convinced that I had the right set of plugs to begin with. They always looked a little black, even when it was running right. I just can't believe that fouled plugs would cause these problems of such biblical proportions. Oh well, only one way to find out. My next question is: is there a site where I can figure out what type of plugs I should be using? I suppose I can start by looking on the Edlebrock page (I've got the Al. RPM heads) for reference. I kind of feel dumb for asking this, but it's something that is often taken for granted and is really not know by too many people. Thanks for the offer Tim, I'll have to rain check on the borrowed labor. Unless you want to weld up the muffler on my wife's Escort... Nah, I wouldn't even ask my worst enemy to do that job. -Thanks again guys -Andy Quote Link to comment Share on other sites More sharing options...
Guest Night_rider_383 Posted June 2, 2001 Share Posted June 2, 2001 You know its hard to be 100% for sure when you cant hear/feel what the car is doing but to me it sounds like timing. Trust me its not hard to get the timing off to where the rotor button is pointing around back of the dist at true TDC. I'll be the 1st to tell ya i have done it a few times and so has a few true pro engine builders. Check your timing make sure you stabed the dist in the engine when it was on the right up stroke. And that your oil pump shaft is stright across. I found most sbc's likes the dist at about 8-10 deg. btdc. On the plug gap. .040 aint enuff your plugs is fouling out cause the spark is to cold. It dont sound right but wider gap = hotter spark to a point. In our 73 chevy c/10, 450 hp 327, we have a gm hei dist., stock coil, re-curved, ac r45ts plugs. and stuck them in stock cause didnt have time to gap them. Well it puffed alittle gas smoke out so the next day we pulled the plugs and opened them to .048 put in and drove it. It had more low end torque and just ran better. Well we pulled them again when it cooled and opened the gap to .053. Drove it had no miss and ran even better. Thats where we left them and thats with the stock hei dist and coil. You should beable to open yours to .060-.065 with the msd Quote Link to comment Share on other sites More sharing options...
TimZ Posted June 2, 2001 Share Posted June 2, 2001 quote: Originally posted by Andrew Bayley: Thanks for the offer Tim, I'll have to rain check on the borrowed labor. Unless you want to weld up the muffler on my wife's Escort... Nah, I wouldn't even ask my worst enemy to do that job. -Thanks again guys -Andy If it's off the car, I don't mind - no guarantees if it's all rust, though. If it's on the car - well, that's a different matter... Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted June 4, 2001 Share Posted June 4, 2001 Andrew, Per Edelbrock general instructions. For RPM heads # 6072, 6073 or 6089. They highly recommend using Champion rc-12yc or equivalent. Hope this helps. Mike Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted June 4, 2001 Share Posted June 4, 2001 Andy, I've also got the RPM heads, straight plug type. Im not at home right now but I have a install sheet I received with my heads. Will post their recommendations when I get home. I do know they are champions that they recommend just dont remember number. Gapped to 40 I believe. Mike Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted June 8, 2001 Author Share Posted June 8, 2001 Thanks Mike, I just saw something on Edelbrock's Web Page that had the Champion part number "RV17YC6" on it. Then, I look somewhere else and it says to use the RC12YC you mentioned. Jeesh, I would think that this is pretty standard information that everyone with AL heads needs to know. Edelbrock sure doesn't make this information easy to find. Tim, Yeah I was trying to re-attach the muffler while everything was one the car. Fortunetly I was able to use slip connectors and everything seems to be sealing allright. Thanks anyway. -Andy Quote Link to comment Share on other sites More sharing options...
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